Motor vehicle seat belt systems commonly have a shoulder belt retractor mounted on the door pillar relatively near the floor. The belt exits the retractor and travels upwardly along the pillar where the belt extends through a guide loop which is mounted high on the pillar to deflect the belt diagonally downward across the occupant upper torso.
Such guide loops are commonly comprised of a sheet metal stamping or a bent rod which define a belt slot through which the belt slides. During such sliding movement of the belt, the belt bears upon the lower wall of the slot. Various prior art guide loops are disclosed in Tolfsen 4,052,772, in which FIGS. 1-4 show various arrangements by which the lower wall defining the belt slot may be modified to provide a somewhat rounded surface and avoid sharp edges in the area of contact with the belt. In FIG. 2 the guide loop has a suitable cover, such as plastic, which provides the rounded surface. In FIG. 3 the guide loop is stamped out of a somewhat thicker steel plate and at least the lower wall of the belt slot is forged to a rounded configuration. FIG. 4 shows the guide loop constructed of a round steel loop which conveniently provides a rounded surface for the belt to slide over. In FIGS. 2 and 3 of Tolfsen, the outer edges of the belt slot are turned upwardly.
Another prior art patent, Fisher U.S. Pat. No. 3,959,855, discloses three separate plastic elements which fit over the lower wall of the belt slot to provide a continuous plastic wall covering the belt slot to prevent the belt from reversing and folding upon itself or being bunched up.
Although all of these arrangements have been proven to provide a suitably strong slidable support for the seat belt and have been proven to function in the restraint of seated occupants under emergency conditions, the present invention provides a further improvement in such guide loops.